Reception apparatus, reception method, program, and information processing system

ABSTRACT

Disclosed herein is a reception apparatus including: a reception portion configured to receive audio video content; a trigger extraction portion configured to extract trigger information for operating an application program transmitted along with the audio video content and executed in interlocked relation to the audio video content; a table acquisition portion configured to acquire a correspondence table for associating the trigger information with commands for controlling the operation of the application program; a command determination portion configured such that, based on the acquired correspondence table, the command determination portion determines the commands associated with the extracted trigger information; and a control portion configured to control the operation of the application program in response to the determined commands.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority of ProvisionalApplication Ser. No. 61/531,360, filed on Sep. 6, 2011, the entirecontent of which is incorporated herein by reference.

BACKGROUND

This technology relates to a reception apparatus, a reception method, aprogram, and an information processing system. More particularly, thistechnology relates to a reception apparatus, a reception method, aprogram, and an information processing system for providing applicationprograms executed in interlocked relation to AV (audio video) contentsuch as digital TV (television) programs.

As a service expected to gain widespread acceptance, the receptionapparatus for receiving digital TV broadcast signals may acquire from aserver on the Internet application programs to be executed ininterlocked relation to digital TV programs and execute the applicationprograms thus acquired. Technological studies are now underway toimplement such a hybrid service combining broadcasting withcommunication (e.g., see Japanese Patent Laid-open No. 2006-245653).

SUMMARY

When the reception apparatus receives digital TV broadcast signals notdirectly but via broadcast transmission channels such as a CATV (cabletelevision) network or a satellite communication network, implementingthe service of executing application programs in interlocked relation todigital TV programs requires the reception apparatus to be notified ofinformation about the service in question via the broadcast transmissionchannels and a dedicated terminal.

In that case, broadcast transmission channel equipments and dedicatedterminals need to be renovated. It is also necessary to obtainpermission from the broadcast operator relaying TV programs. Thus therehas been the need to provide application programs that can be executedin interlocked relation to digital TV programs without recourse to suchwork. At present, however, technical systems have yet to be establishedto provide such application programs for execution in interlockedrelation to audio video content such as digital TV programs.

In view of the above circumstances, this technology has been made toprovide application programs to be executed in interlocked relation toaudio video content such as digital TV programs.

According to a first embodiment of this technology, there is provided areception apparatus including: a reception portion configured to receiveaudio video content; a trigger extraction portion configured to extracttrigger information for operating an application program transmittedalong with the audio video content and executed in interlocked relationto the audio video content; a table acquisition portion configured toacquire a correspondence table for associating the trigger informationwith commands for controlling the operation of the application program;a command determination portion configured such that, based on theacquired correspondence table, the command determination portiondetermines the commands associated with the extracted triggerinformation; and a control portion configured to control the operationof the application program in response to the determined commands.

Preferably, the reception apparatus of this technology may furtherinclude an output portion configured to output the audio video content,or the audio video content as well as the application program; whereinthe table acquisition portion may acquire the correspondence table ifthe audio video content being output is changed in substance.

Preferably, the trigger information may include determinationinformation for determining an information processing apparatusproviding the correspondence table and first identification informationfor identifying the audio video content; and if the determinationinformation or the first identification information included in theextracted trigger information is changed, the table acquisition portionmay acquire the correspondence table from the information processingapparatus in accordance with the determination information and the firstidentification information.

Preferably, the correspondence table may further associate the triggerinformation and the commands with second identification information foridentifying the application program; and the command determinationportion may determine the commands associated with the triggerinformation regarding each of the application programs identified by thesecond identification information associated with the extracted triggerinformation.

Preferably, the control portion may control the operation of one or aplurality of the application programs in response to the determinedcommands.

Preferably, the trigger information may further include informationindicative of the probability of the trigger information itself becomingeffective; and if the trigger information becomes effective, the controlportion may control the operation of the application program in responseto the commands.

The commands may designate acquisition or registration, acquisition oractivation, firing of an event, suspension of the application program,or termination of the application program; and in response to each ofthe commands, the control portion may control acquisition orregistration, acquisition or activation of the application program,firing of an event into the currently executing application program,suspension, or termination of the currently executing applicationprogram.

Also according to the first embodiment of this technology, there isprovided a reception method or a program functionally corresponding tothe above-outlined reception apparatus according to the first embodimentof this technology.

Where the reception apparatus, reception method, and program accordingto the first embodiment of this technology are in use, audio videocontent is received; trigger information is extracted for operating anapplication program transmitted along with the audio video content andexecuted in interlocked relation to the audio video content; acorrespondence table is acquired for associating the trigger informationwith commands for controlling the operation of the application program;based on the acquired correspondence table, the commands associated withthe extracted trigger information are determined; and the operation ofthe application program is controlled in response to the determinedcommands.

The reception apparatus may be an independent apparatus or an internalblock constituting part of a single apparatus.

According to a second embodiment t of this technology, there is providedan information processing system including a reception apparatus, afirst information processing apparatus, and a second informationprocessing apparatus. The reception apparatus includes a receptionportion configured to receive audio video content; a trigger extractionportion configured to extract trigger information for operating anapplication program transmitted along with the audio video content andexecuted in interlocked relation to the audio video content; a tableacquisition portion configured to acquire from the first informationprocessing apparatus a correspondence table for associating the triggerinformation with commands for controlling the operation of theapplication program; a command determination portion configured todetermine, based on the acquired correspondence table, the commandsassociated with the extracted trigger information; and a control portionconfigured to control the operation of the application program acquiredfrom the second information processing apparatus in response to thedetermined commands. The first information processing apparatus includesa first provision portion configured to provide the correspondence tablein response to a query from the reception apparatus. The secondinformation processing apparatus includes a second provision portionconfigured to provide the application program in response to a queryfrom the reception apparatus.

Where the information processing system according to the secondembodiment of this technology is in use, the reception apparatusreceives audio video content, extracts trigger information for operatingan application program transmitted along with the audio video contentand executed in interlocked relation to the audio video content,acquires from the first information processing apparatus acorrespondence table for associating the trigger information withcommands for controlling the operation of the application program; basedon the acquired correspondence table, determines the commands associatedwith the extracted trigger information, and controls the operation ofthe application program acquired from the second information processingapparatus in response to the determined commands; the first informationprocessing apparatus provides the correspondence table in response to aquery from the reception apparatus; and the second informationprocessing apparatus provides the application program in response to aquery from the reception apparatus.

According to the first and the second embodiments of this technology, itis possible to provide application programs for execution in interlockedrelation to audio video content such as digital TV programs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing a typical configuration of abroadcasting system;

FIG. 2 is a schematic view showing a typical structure of a receptionapparatus;

FIG. 3 is a schematic view showing operations of component apparatusesmaking up the broadcasting system;

FIGS. 4A and 4B are schematic views each showing an example in whichtrigger information is embedded into a video signal;

FIG. 5 is a schematic view showing the concept of transmitting thetrigger information included in PCR packets of a TS;

FIG. 6 is a schematic view showing a specific layout of the triggerinformation in a PCR packet;

FIG. 7 is a schematic view showing typical items included in the triggerinformation;

FIG. 8 is a schematic view showing a typical description of the triggerinformation;

FIG. 9 is a schematic view showing typical detail specifications of aTPT;

FIG. 10 is a schematic view showing a typical description of the TPT;

FIG. 11 is a schematic view showing typical relations of correspondencebetween trigger information and commands;

FIG. 12 is a schematic view showing state transitions of a databroadcast application;

FIG. 13 is a schematic view showing relations between commands and statetransitions;

FIG. 14 is a flowchart showing a trigger information handling process;

FIG. 15 is a schematic view showing a typical operation scenario;

FIG. 16 is a schematic view showing a typical configuration of acommunication system; and

FIG. 17 is a schematic view showing a typical structure of a computer.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Some preferred embodiments of this technology will now be describedbelow in reference to the accompanying drawings.

First Embodiment Typical Configuration of a Broadcasting System

FIG. 1 shows a broadcasting system 1 as an embodiment of thistechnology. The broadcasting system 1 is made up of a broadcast unit 11,a reception apparatus 12, a TPT server 13, and an application server 14.The reception apparatus 12, the TPT server 13, and the applicationserver 14 are interconnected via the Internet 20.

The broadcast unit 11 is designed to transmit digital TV broadcastsignals of audio video content such as digital TV programs and CMs(commercial messages). In the ensuing description, emphasis will beplaced on digital TV programs as a typical example of audio videocontent.

Also, the broadcast unit 11 transmits trigger information as part of thedigital TV broadcast signals, the trigger information being devised tooperate a data broadcast application executed in interlocked relation toa digital TV program. The data broadcast application is an applicationprogram intended for data broadcasting purposes and executed ininterlocked relation to the digital TV program.

The trigger information, when transmitted, is inserted into video oraudio signals of the digital TV program or placed into transport streams(referred to as TS hereinafter) of the digital TV broadcast signals. Thetrigger information will be discussed later in detail by referring toFIGS. 4A and 4B to 8.

The reception apparatus 12 receives the digital TV broadcast signalstransmitted from the broadcast unit 11, thereby acquiring images andsounds of the digital TV program. The reception apparatus 12 outputs theacquired images to a display device and the sounds to speakers.

The reception apparatus 12 may exist as a stand-alone unit or as abuilt-in unit in a TV set or in a video recorder, for instance. Adetailed structure of the reception apparatus 12 will be discussed laterin reference to FIG. 2.

Also, in response to the trigger information from the broadcast unit 11,the reception apparatus 12 may access the TPT server 13 via the Internet20 to acquire a TPT.

The TPT server 13 is a server which manages TPTs and which is offeredfor example by a broadcast operator or the like broadcasting digital TVprograms using the broadcast unit 11. A TPT (trigger parameter table) isa correspondence table that associates trigger information with commandsfor controlling data broadcast applications. In response to a query fromthe reception apparatus 12, the TPT server 13 provides a TPT under itsmanagement to the reception apparatus 12 via the Internet 20.

Based on the TPT acquired from the TPT server 13, the receptionapparatus 12 determines the command corresponding to the triggerinformation from the broadcast unit 11. And in response to the commandthus determined, the reception apparatus 12 controls the operation ofthe data broadcast application. Also, in response to the determinedcommand, the reception apparatus 12 accesses the application server 14via the Internet 20 to acquire the data broadcast application.

The application server 14 is a server which is offered for example by abroadcast operator or the like broadcasting digital TV programs usingthe broadcast unit 11 and which manages the data broadcast applicationsexecuted in interlocked relation to the digital TV program broadcastedby the broadcast unit 11. In response to a query from the receptionapparatus 12, the application server 14 provides a data broadcastapplication under its management to the reception apparatus 12 via theInternet 20.

The broadcasting system 1 is structured as explained above.

[Typical Structure of the Reception Apparatus]

FIG. 2 shows a typical structure of the reception apparatus 12 includedin FIG. 1.

The reception apparatus 12 is made up of a tuner 51, a demultiplexingportion 52, an audio decoder 53, an audio output portion 54, a videodecoder 55, a video output portion 56, a trigger extraction portion 57,a communication interface (I/F) 58, a TPT analysis portion 59, a controlportion 60, a memory 61, an operation portion 62, an application engine63, a cache memory 64, and an application memory 65.

The tuner 51 receives the digital TV broadcast signals corresponding tothe channel selected by a user, demodulates the received signal, andoutputs the resulting TS to the demultiplexing portion 52.

The demultiplexing portion 52 demultiplexes the TS input from the tuner51 into an audio coded signal and a video coded signal which are outputto the audio decoder 53 and the video decoder 55, respectively.

The audio decoder 53 decodes the input audio coded signal, and outputsthe resulting audio signal to the audio output portion 54. The audiooutput portion 54 outputs the input audio signal to downstream speakers.

The video decoder 55 decodes the input video coded signal, and outputsthe resulting video signal to the video output portion 56 and thetrigger extraction portion 57. The video output portion 56 outputs thevideo signal input from the video decoder 55 to a downstream displaydevice.

The trigger extraction portion 57 continuously monitors the video signalinput from the video decoder 55, extracts the trigger informationembedded in the video signal, and supplies the extracted triggerinformation to the control portion 60.

Although it is assumed here that the trigger information is embedded inthe video signal for example, if the trigger information is placed inthe TS, then the trigger extraction portion 57 extracts the triggerinformation from PCR (program clock reference) packets which are inputfrom the demultiplexing portion 52 and which include the triggerinformation in question. And if the trigger information is embedded inthe audio signal, the trigger extraction portion 57 continuouslymonitors the audio signal input from the audio decoder 53, and extractsthe trigger information embedded in the audio signal.

Also, in accordance with the extracted trigger information, the triggerextraction portion 57 controls the communication I/F 58 to access theTPT server 13 via the Internet 20 to request a TPT therefrom. Thecommunication I/F 58 receives the TPT sent from the TPT server 13 viathe Internet 20, and feeds the received TPT to the TPT analysis portion59.

The TPT analysis portion 59 acquires the TPT from the communication I/F58. The TPT analysis portion 59 analyzes the acquired TPT before placingit into an internal memory (not shown) for storage. Also, in response toa request from the control portion 60, the TPT analysis portion 59supplies the control portion 60 with the TPT held in the memory.

The control portion 60 controls the operations of the componentsconstituting the reception apparatus 12 by executing control programsstored beforehand in the memory 61. The memory 61 retains in advance thecontrol programs to be executed by the control portion 60. The controlprograms may be appropriately updated based on the digital TV broadcastsignal or on update data acquired via the Internet 20. The operationportion 62 accepts various operations from the user, and notifies thecontrol portion 60 of operation signals corresponding to the acceptedoperations.

Also, based on the TPT from the TPT analysis portion 59, the controlportion 60 determines the command corresponding to the triggerinformation from the trigger extraction portion 57. In response to thecommand thus determined, the control portion 60 may control acquisitionor registration of a data broadcast application, acquisition orexecution of the application, event firing in the application,suspension of the application, termination of the application, or thelike.

The application engine 63 under control of the control portion 60controls the communication I/F 58 to access the application server 14via the Internet 20 to request a data broadcast application from theapplication server 14. The communication I/F 58 receives the databroadcast application sent from the application server 14 via theInternet 20, and retains the received data broadcast application in thecache memory 64.

The application engine 63 under control of the control portion 60 readsthe data broadcast application held in the cache memory 64 and executesthe retrieved data broadcast application. The video signal of thecurrently executing data broadcast application is fed to the videooutput portion 56.

The video output portion 56 combines the video signal input from theapplication engine 63 with the video signal input from the video decoder55, and outputs the combined signal to the downstream display device.

The application memory 65 is composed of a work memory 65A and a savememory 65B. The application engine 63 records to the work memory 65A thedata about the currently executing data broadcast application(specifically, the data may include the layer of the currently displayedinformation). When suspending the currently executing data broadcastapplication, the application engine 63 moves the data held in the workmemory 65A of the application memory 65 into the save memory 65B. Andwhen reactivating the suspended data broadcast application, theapplication engine 63 moves the data held in the save memory 65B intothe work memory 65A so as to restore the state in effect before thesuspension.

The reception apparatus 12 is structured as explained above.

[Operations of the Components of the Broadcasting System]

Explained next in reference to FIG. 3 is an outline of the operations ofthe components making up the broadcasting system 1.

In the broadcasting system 1 of FIG. 3, the broadcast unit 11 transmits(S1) the digital TV broadcast signal of a digital TV program (indicatedas “Content” in the drawing) including trigger information (indicated as“Trigger” in the drawing). The digital TV broadcast signal also includesmetadata (indicated as “Metadata” in the drawing) about the digital TVprogram in question.

When receiving the digital TV broadcast signal from the broadcast unit11 via a CATV network or a satellite communication network, thereception apparatus 12 receives (S2) a signal resulting from conversionby a dedicated terminal such as a set-top box 15 (indicated as “STB (SetTop Box)” in the drawing) through an HDMI (High Definition MultimediaInterface). In this case, the output from the set-top box 15 includesonly the digital TV program and trigger information; the receptionapparatus 12 cannot use the metadata.

That is, besides the case in which the digital TV broadcast signal isdirectly received (S1), the reception apparatus 12 can also extract thetrigger information transmitted together with the digital TV broadcastsignal when the signal is received via the set-top box 15 (S2). And thereception apparatus 12 determines whether or not to acquire a TPT basedon server determination information for determining the TPT server 13 oron content identification information for identifying audio videocontent, the information being included in the extracted triggerinformation. Incidentally, the server determination informationcorresponds to a domain_name to be discussed later in reference to FIG.7, and the content identification information corresponds to aprogram_id in FIG. 7.

When deciding to acquire a TPT, the reception apparatus 12 accesses theTPT server 13 via the Internet 20 to request the TPT therefrom (S3).

For example, suppose that the user at the reception apparatus 12 changesthe channel of the currently selected digital TV program to another. Inthat case, the server determination information included in the triggerinformation varies from one broadcast operator to another broadcastingthe programs before and after the channel change. Because the channelchange renders the server determination information different, thereception apparatus 12 determines to acquire the TPT, and requests theTPT regarding the channel or program following the channel or programchange from the TPT server 13.

As another example, suppose that one digital TV program has ended andanother digital TV program has started on the same channel in thereception apparatus 12. In that case, the content identificationinformation included in the trigger information varies from one programto another before and after the program change. Because the programchange renders the content identification information different, thereception apparatus 12 determines to acquire the TPT, and requests theTPT regarding the program or channel following the program or channelchange from the TPT server 13.

In the foregoing examples, it was explained that the TPT is acquiredfollowing the channel or program change. Alternatively, the receptionapparatus 12 may acquire TPTs using other timings. That is, when thecontent of the currently selected digital TV program is changed, thereception apparatus 12 requests a TPT reflecting the changed contentfrom the TPT server 13.

In response to a query from the reception apparatus 12, the TPT server13 determines the TPT and transmits (S4) the determined TPT (indicatedas “TPT” in the drawing) to the reception apparatus 12 via the Internet20. The reception apparatus 12 receives the TPT from the TPT server 13via the Internet 20 and retains the received TPT.

More specifically, the TPT server 13 manages the TPTs corresponding toeach of diverse pieces of audio video content such as digital TVprograms and CMs. The TPT server 13 determines the TPT corresponding tothe audio video content identified by the content identificationinformation or the like included in the TPT request from the receptionapparatus 12, and transmits the TPT thus determined to the receptionapparatus 12.

For example, the TPT server 13 determines the TPT corresponding to thedigital TV program broadcast by the broadcast operator offering the TPTserver 13, within a predetermined time period (e.g., several hours, oneday, or the like) following the time the digital TV program identifiedby the content identification information or the like from the receptionapparatus 12 is started, and transmits the determined TPT to thereception apparatus 12. This allows the reception apparatus 12 toacquire the TPTs regarding all programs broadcast within thepredetermined time period by the broadcast operator corresponding to thechannel in effect after the channel change.

As another example, the TPT server 13 determines the TPT correspondingto the digital TV program identified by the content identificationinformation or the like from the reception apparatus 12, and transmitsthe TPT thus determined to the reception apparatus 12. In this manner,the reception apparatus 12 acquires the TPT regarding the program ineffect after the program change.

That is, when the content of the currently selected digital TV programis changed, the reception apparatus 12 acquires the TPT corresponding tothe changed content only once.

And when the trigger information is extracted from the broadcast unit11, the reception apparatus 12 references the TPT it retains so as todetermine the command corresponding to the trigger information inquestion. In response to the command thus determined, the receptionapparatus 12 accesses the application server 14 via the Internet 20, andrequests therefrom (S5) the data broadcast application to be executed ininterlocked relation to the currently selected digital TV program.

In response to a query from the reception apparatus 12, the applicationserver 14 transmits (S6) the data broadcast application (indicated as“Application” in the drawing) to the reception apparatus 12 via theInternet 20. The reception apparatus 12 acquires the data broadcastapplication from the application server 14 via the Internet 20 andactivates the acquired application.

If the trigger information is extracted during execution of the databroadcast application, the reception apparatus 12 determines the commandcorresponding to the extracted trigger information by use of the TPT.And the data broadcast application is subjected to such operations asevent firing, suspension, termination, etc., depending on the determinedcommand.

In the broadcasting system 1, as explained above, the receptionapparatus 12 operates in interlocked relation to the TPT server 13 andapplication server 14 in accordance with the trigger information fromthe broadcast unit 11. This allows the reception apparatus 12 to acquireand execute the data broadcast application executed in interlockedrelation to the currently selected digital TV program. Also, the triggerinformation from the broadcast unit 11 may be sent to the receptionapparatus 12 via a dedicated terminal such as the set-top box 15. Thismeans that the broadcasting system 1 can provide data broadcastapplications without renovating the broadcast transmission channelequipment such as a CATV network or the dedicated terminal and withoutobtaining permission from the relaying broadcast operator.

[Method for Transmitting the Trigger Information]

Explained next is a method for transmitting trigger information.

FIGS. 4A and 4B show two examples in which trigger information isembedded into the video signal of a digital TV program.

FIG. 4A shows an example in which trigger information is turned into atwo-dimensional barcode that is superposed onto a predetermined positionof a video signal image (at the bottom right corner in this example).FIG. 4B shows an example in which trigger information is turned into avideo code that is superposed onto several lines at the bottom of thevideo signal image. The trigger information shown in FIGS. 4A and 4B isextracted by the trigger extraction portion 57 of the receptionapparatus 12.

In both examples in FIGS. 4A and 4B, the trigger information is placedon the video of the digital TV program, so that the trigger informationmay be informed to reception apparatuses such as those utilizing CATVnetworks or satellite communication networks (e.g., reception apparatus12 in FIG. 3).

Also in both examples in FIGS. 4A and 4B, the trigger informationsuperposed on the video (two-dimensional barcode or video code) can berecognized visually by the user of the reception apparatus 12. If thatis not desirable, the trigger information superposed on the video may bemasked using the same pixels as those surrounding the information beforeit is displayed.

Although FIGS. 4A and 4B show examples in which the trigger informationis embedded in the video signal of the digital TV program, this is notlimitative of the position where the trigger information is placed or ofthe method for transmitting the trigger information, as explained above.In another example, the trigger information may be placed in PCRs of theTS.

FIG. 5 shows the concept of transmitting the trigger information placedin PCR packets of the TS carrying a digital TV broadcast signal.

As shown in FIG. 5, not all PCR packets accommodate the triggerinformation; the trigger information may be placed into PCR packets onlyin a suitably timed manner permitting interlocking with the digital TVprogram. Usually, PCR packets pass through the PID filter of a CATVretransmission unit, so that the trigger information may also beinformed to reception apparatuses utilizing CATV networks or satellitecommunication networks (e.g., reception apparatus 12 in FIG. 3). Also,the trigger information may be placed in the user data region of a videocoded stream or an audio coded stream.

Furthermore, one trigger information is transmitted consecutivelyseveral times in consideration of radio interference, a capture failure(reception miss) of the reception apparatus 12 or the like.

FIG. 6 shows the position where trigger information is held in a PCRpacket. The PCR packet is a TS packet with its adaptation_field holdinga PCR. The trigger information (Trigger Info_descriptor) is held in atransport_private_data_byte following the PCR. When the triggerinformation is held this way, a transport_private_data_flag amongVarious_flags in front of the PCR is set to 1.

[Details of the Trigger Information]

Explained next are details of trigger information. FIG. 7 shows typicalinformation items included in the trigger information.

A “domain_name” is information for determining the TPT server 13. Forexample, the domain_name specifies information indicative of the domainname of the TPT server 13. That is, the TPT server 13 is provided bybusiness operators such as the broadcast operator broadcasting digitalTV programs using the broadcast unit 11. Thus the domain name variesfrom one business operator to another.

A program_id is information for identifying audio video content such asa digital TV program. That is, the reception apparatus 12 informs theprogram_id included in the trigger information to the TPT server 13, sothat the TPT server 13 can identify the digital TV program fordetermining the TPT based on the program_id from the reception apparatus12.

As explained above, the domain_name corresponds to server determinationinformation and the program_id corresponds to content identificationinformation.

A trigger_id is information for identifying this trigger information.Also, the trigger_id designates a specific command.

A trigger_validity is information indicative of the probability of thistrigger information becoming valid. A server access dispersion parametervalue N is set as this information, the value N indicating theprobability that each reception apparatus 12 having received thistrigger information performs its processing in accordance with thereceived trigger information. Setting this value makes it possible todisperse the attempts by a plurality of reception apparatuses 12 toaccess the TPT server so as to acquire TPTs therefrom, the accessattempts not being concentrated on a limited period.

For example, if it is desired to disperse the access attempts frompotentially numerous reception apparatuses 12 to the TPT server 13 intofour times, the same trigger information is transmitted four times andthe inverse of the probability is designated in the trigger_validityusing an integer. That is, the server access dispersion parameter valueN may be set to 4 for the first trigger information, to 3 for the secondtrigger information, to 2 for the third trigger information, and to 1for the fourth trigger information.

Furthermore, the trigger_validity is an optional item, so that thetrigger_validity may be designated only if the attempts to access theTPT server 13 are desired to be dispersed. And if the itemtrigger_validity is not designated in the trigger information, thereception apparatus 12 regards the server access dispersion parametervalue N as 1 and considers that this trigger information is valid.

[Typical Description of the Trigger Information]

FIG. 8 is a schematic view showing a typical description of the triggerinformation.

As shown in FIG. 8, the trigger information is typically made up of thedomain_name, program_id, trigger_id, and a value for designatingtrigger_validity indicated in FIG. 7, as well as a character stringconcatenating predetermined characters such as “/,” “?id=” and the like.For example, if the domain_name is “abc.tv,” the program_id is “300,”and the trigger_id is “1,” then the character string indicative of thetrigger information is “abc.tv/300?id=1.”

That is, attaching “http://” to the beginning of this character stringconstitutes a character string “http://abc.tv/300?id=1” indicative ofthe URL (Uniform Resource Locator) at which to access the TPT server 13.Also, because this URL is suffixed with a query character stringid=<trigger_id>, the TPT server 13 can obtain the parameter involved byuse of the GET method under HTTP (HyperText Transfer Protocol). And ifthe trigger_id indicates a specific value for example, the TPT server 13can transmit to the reception apparatus 12 the TPT determined inaccordance with the parameter value.

Since the trigger_validity is an optional item as explained above, acharacter string vrate=<trigger_validity> is included in the triggerinformation and attached to the URL as the query character string onlyif the trigger_validity is set.

The method for describing the trigger information is arbitrary and notlimited to the description example shown in FIG. 8.

The trigger information is structured as explained above.

[Details of the TPT]

Explained next are details of the TPT. FIG. 9 is a schematic viewshowing typical detailed specifications of a TPT.

As shown in FIG. 9, the TPT is primarily composed of tpt elements andcommand elements.

In the tpt element, information about the TPT is described. The tptelement includes a program attribute.

In the program attribute, information for identifying the TPT isdesignated. For example, in the program attribute, a character stringconcatenating domain_name and program_id using “/” is designated.

That is, the control portion 60 compares the values of domain_name andprogram_id included in the extracted trigger information with the valuesof the program attribute in the retained TPT and, only if these valuesmatch, determines the command corresponding to the trigger information.For example, although radio interference or capture failure (receptionmiss) on the reception apparatus 12 may have prevented the receptionapparatus 12 from retaining the appropriate TPT, the control portion 60can reliably determine the expected command by checking whetherdomain_name and program_id match in determining the command.

In the command element, information about the command is described. Thecommand element includes an id attribute, a destination attribute, andan action attribute.

In the id attribute, information for identifying the command isdesignated. Furthermore, in the id attribute, the value corresponding totrigger_id included in the trigger information is designated.

In the destination attribute, the device targeted for data broadcastapplication control exercised by this command is designated. Here, if anexternal device is connected to the reception apparatus 12 besides thereception apparatus body (reception apparatus 12), the external deviceis designated as a command target device. For example, in thedestination attribute, “receiver” is designated if the receptionapparatus 12 is the command target device, and “external_1” or“external_2” is designated if the external device is the command targetdevice. If the destination attribute is not designated, “receiver” isassumed to be designated.

The action attribute indicates that this command is one of the commands“execute,” “register,” “suspend,” “terminate,” and “event.”

The execute command (execute) is a command that orders the receptionapparatus 12 to acquire or activate the data broadcast application.

The register command (register) is a command that orders the receptionapparatus 12 to acquire or register the data broadcast application.Here, registration of the data broadcast application means associatingthe acquired data broadcast application with its priority and expirationdate which are then stored. The data broadcast application is managed bythe control portion 60 in accordance with its priority and preservationdate.

The suspend command (suspend) is a command that orders the receptionapparatus 12 to suspend the currently executing data broadcastapplication.

The terminate command (terminate) is a command that orders the receptionapparatus 12 to terminate the currently executing data broadcastapplication.

The event command (event) is a command that orders the receptionapparatus 12 to fire an event on the currently executing data broadcastapplication.

That is, in the action attribute for example, the command “execute” isdesignated if acquisition or activation of the data broadcastapplication is ordered; the command “register” is designated ifacquisition or registration of the data broadcast application isordered; the command “suspend” is designated if suspension of the databroadcast application is ordered; the command “terminate” is designatedif termination of the data broadcast application is ordered; and thecommand “event” is designated if an event is fired on the currentlyexecuting data broadcast application.

In an application element, information about the data broadcastapplication is described. The application element includes an idattribute, a type attribute, a url attribute, a priority attribute, andan expire_date attribute.

In the id attribute, an application ID for identifying this databroadcast application is designated. In the type attribute, anapplication type indicative of information about the file attribute andthe like of this data broadcast application is designated. In the urlattribute, where the command is the execute or register command, anapplication URL indicating the location from which to acquire this databroadcast application is designated. Thus the URL of the applicationserver 14 is designated in the url attribute.

In the priority attribute, information indicating the priority foracquiring and retaining the data broadcast application corresponding tothis command is designated. In the expire_date attribute, informationindicating the expiration date of the data broadcast application isdesignated. When a data broadcast application is registered, anapplication expiration date and a retention priority of the databroadcast application are stored. The data broadcast applications arethen managed in accordance with these expiration dates and retentionpriorities.

Furthermore, where the command is the execute or register command, theurl attribute and expire_date attribute are mandatory items. Usually,“0” is designated in the priority attribute; if the priority is desiredto be higher, “1” is designated.

In an event element, information about the event command is described.The event element includes an id attribute and a data element.

In the id attribute, where the command is the event command, an event IDfor identifying the event to be fired on the data broadcast applicationdesignated by the application ID is designated. And in the data element,where the command is the event command, event addition data to bereferenced upon firing of an event is described.

Furthermore, the event element is a mandatory item if the actionattribute is “event.”

[Typical Description of the TPT]

FIG. 10 is a schematic view showing a typical description of the TPT.

In the example of FIG. 10, “abc.tv/300” is designated in the programattribute of the tpt element. Specifically, this means, for example,that the TPT is destined for the digital TV program (program_id=“300”)broadcast by abc broadcasting station (domain_name=“abc.tv”). In thistpt element, seven command elements are described, although not all ofthem are shown for purpose of simplifying the explanation.

In the first command element, “1” is designated as the id attribute,“receiver” is designated as the destination attribute, and “register” isdesignated as the action attribute. That is, this command (id=1) servesas the register command for the reception apparatus 12. And between thestart tag and the end tag of the command element, the applicationelement is described. In the application element, “1” is designated asthe id attribute, “html” is designated as the type attribute,“xxx.com/yyy1” is designated as the url attribute, and “2011-01-21” isdesignated as the expire_date attribute. That is, this applicationelement means that the data broadcast application (id=1) described inHTML (Hyper Text Markup Language) can be acquired from the applicationserver 14 determined by the URL “xxx.com/yyy1.”

Likewise, the second command element indicates that this command (id=2)serves as the execute command for the reception apparatus 12. It alsomeans that the data broadcast application (id=1) to be acquired inresponse to the execute command can be acquired from the applicationserver 14 determined by the URL “xxx.com/yyy1.”

The third command element indicates that this command (id=3) serves asthe event command for the data broadcast application (id=1) executed bythe reception apparatus 12. And between the start tag and the end tag ofthis command element, the application element and event element aredescribed. In the application element, “1” is designated as the idattribute. And in the event element, “event1” is designated as the idattribute, and “zzzzzzz . . . z” is described as the data element. Thatis, with an event fired by this command, the data “zzzzzzz . . . z” isused by the data broadcast application.

The fourth command element indicates that this command (id=4) serves asthe suspend command for the data broadcast application (id=1) executedby the reception apparatus 12. Furthermore, the fifth command elementindicates that this command (id=5) serves as the terminate command forthe data broadcast application (id=1) executed by the receptionapparatus 12.

The sixth command element indicates that this command (id=12) serves asthe execute command for the reception apparatus 12. And in theapplication element between the start tag and the end tag of the commandelement, “2” is designated as the id attribute, “html” is designated asthe type attribute, “xxx.com/yyy2” is designated as the url attribute,and “2011-01-22” is designated as the expire_date attribute. That is, itmeans that the data broadcast application (id=2) to be acquired inresponse to the execute command can be acquired from the applicationserver 14 determined by the URL “xxx.com/yyy2.”

Likewise, the seventh command element indicates that this command(id=15) serves as the terminate command for the data broadcastapplication (id=2) executed by the reception apparatus 12.

The method for describing the TPT is arbitrary and not limited to thedescription example shown in FIG. 10.

The TPT is structured as explained above.

[Relations of Correspondence Between the Trigger Information and theCommands]

Explained next is an example of processing in which the commandassociated with the trigger information is determined using the TPT.FIG. 11 is a schematic view showing typical relations of correspondencebetween the trigger information and the commands.

As shown in FIG. 11, after extracting the trigger information from thevideo signal obtained from the TS, the reception apparatus 12 determineswhether or not to acquire a TPT from the TPT server 13 based on the itemdomain_name or program_id included in the trigger information.

For example, if the trigger information “abc.tv/300?id=1” is extractedand if the value of the item program_id included in the most recentlyextracted trigger information is other than “300,” which means theprogram_id has changed, the reception apparatus 12 determines that theTPT is to be acquired. The reception apparatus 12 then acquires the TPTby accessing the TPT server 13 determined by the URL(“http://abc.tv/300?id=1”) obtained by adding “http://” to the beginningof the trigger information.

In this manner, the reception apparatus 12 retains the TPT(program=“abc.tv/300”) shown in FIG. 11. Although the TPT indicated inFIG. 11 corresponds to the above-described TPT in FIG. 10, the TPT inFIG. 11 shows only the id attribute and the action attribute in thecommand element, the id attribute in the application element, andparameters such as URLs or the like for the purpose of simplifying theexplanation.

For example, if the trigger_id included in the first trigger information(“abc.tv/300?id=1”) is “1,” the reception apparatus 12 determines theregister command (Register) corresponding to the id attribute “1” of thecommand element based on the TPT. And in response to the registercommand, the reception apparatus 12 acquires and registers the databroadcast application of which the application ID is “1.”

Next, if the second trigger information (“abc.tv/300?id=2”) is extractedand if the trigger_id included in this trigger information is “2,” thereception apparatus 12 determines the execute command (Execute)corresponding to the id attribute “2” of the command element based onthe TPT. And in response to the execute command, the reception apparatus12 executes the acquired data broadcast application.

Later, if the third trigger information (“abc.tv/300?id=3”) is extractedand if the trigger_id included in this trigger information is “3,” thereception apparatus 12 determines the event command (Event)corresponding to the id attribute “3” of the command element based onthe TPT. And in response to the event command, the reception apparatus12 fires an event on the currently executing data broadcast application.

Thereafter, if further trigger information (“abc.tv/300?id=4”) isextracted (not shown in FIG. 11) and if the trigger_id included in thistrigger information is “4,” the reception apparatus 12 determines thesuspend command (Suspend) corresponding to the id attribute “4” of thecommand element based on the TPT. And in response to the suspendcommand, the reception apparatus 12 suspends the currently executingdata broadcast application. Furthermore, if the execute command(Execute) is determined in accordance with the extracted triggerinformation, the reception apparatus 12 resumes the currently suspendeddata broadcast application in response to the execute command.

Later, if further trigger information (“abc.tv/300?id=5”) is extractedand if the trigger_id included in this trigger information is “5,” thereception apparatus 12 determines the terminate command (Terminate)corresponding to the id attribute “5” of the command element, andterminates the currently executing data broadcast application inresponse to the terminate command.

In the above-described example, it was shown that the data broadcastapplication of which the application ID is “1” is acquired and executed.Alternatively, using different application IDs, the reception apparatus12 can execute a plurality of data broadcast applications. For example,if the data broadcast application executed in interlocked relation to adigital TV program is given the application ID “1” and if the databroadcast application executed in interlocked relation to CMs insertedinto the program is given the application ID “2,” the receptionapparatus 12 can switch the data broadcast application for the programwith that for CMs. For example, in the example of the TPT in FIG. 11,where the trigger_id included in the trigger information ranges from “1”to “5,” the operation of the data broadcast application for the programis controlled; where the trigger_id included in the trigger informationis “12” and “15,” the operation of the data broadcast application forCMs is controlled.

As explained above, upon extracting the trigger information coming fromthe broadcast unit 11, the reception apparatus 12 determines the commandcorresponding to the extracted trigger information based on the retainedTPT, and controls the operation of the data broadcast application inresponse to the command thus determined.

[State Transitions of the Data Broadcast Application]

FIG. 12 is a state transition diagram of a data broadcast applicationoperated by the reception apparatus 12 in response to each of theregister, execute, event, suspend, and terminate commands. As shown inFIG. 12, the state of the data broadcast application is defined to be inone of four states of transition: released state (Released), ready state(Ready), active state (Active), and suspended state (Suspend).

The released state is a state in which the reception apparatus 12 hasyet to acquire the data broadcast application. The ready state is astate in which the data broadcast application in question is registered(in the reception apparatus 12) but has yet to be activated. The activestate is a state in which the data broadcast application is started andcurrently executing. The suspended state is a state in which thecurrently executing data broadcast application has been activatedsuspended and information indicative of the suspended status is retainedin the save memory 65B.

If the register command is received while the data broadcast applicationis in the released state (i.e., yet to be acquired by the receptionapparatus 12), the data broadcast application in question is acquired(registered) in accordance with the register command. This puts the databroadcast application in the ready state.

If the execute command is received while the data broadcast applicationis in the ready state, the data broadcast application in question isactivated in accordance with the execute command. This puts the databroadcast application in the active state.

If the execute command is received while the data broadcast applicationis in the released state (i.e., yet to be acquired by the receptionapparatus 12), the data broadcast application in question is acquiredand activated in accordance with the execute command. This puts the databroadcast application in the active state.

If the suspend command is received while the data broadcast applicationis in the active state, the currently executing data broadcastapplication is suspended in accordance with the suspend command. Thisputs the data broadcast application in the suspended state.

If the execute command is received while the data broadcast applicationis in the suspended state, the suspended data broadcast application isresumed in accordance with the execute command. This puts the databroadcast application in the active state.

If the terminate command is received while the data broadcastapplication is in the active or suspended state, the currently executingdata broadcast application is terminated in accordance with theterminate command. This puts the data broadcast application in the readystate (“A” in FIG. 12). Incidentally, in addition to the transitionbrought about by the terminate command, the transition to the readystate may also take place in other occasions such as when another databroadcast application is executed.

Also, if the application expiration date of the command expires whilethe data broadcast application is in the ready, active, or suspendedstate, the data broadcast application is placed in the released state(“B” in FIG. 12).

FIG. 13 indicates relations between commands and state transitions.

FIG. 13 schematically shows that the reception apparatus 12 using theTPT determines the commands corresponding to the trigger informationtransmitted along with the digital TV broadcast signal of a digital TVprogram and controls the operation of the data broadcast applications inresponse to the commands thus determined.

The reception apparatus 12 in FIG. 13 executes two data broadcastapplications having different application IDs, one of the twoapplications being called the first data broadcast application to bedistinguished from the other application called the second databroadcast application. Another data broadcast application executed bysome other device such as an external device connected to the receptionapparatus 12 may be called the third data broadcast application.Furthermore, the reception apparatus 12 may not respond to all triggerinformation extracted; the apparatus ignores (“ignore” in FIG. 13) thetrigger information already handled.

If the reception apparatus 12 acquires, retains and registers the firstdata broadcast application in response to the register command while thefirst data broadcast application is in the released state (i.e., yet tobe acquired by the reception apparatus 12), then the first databroadcast application is placed into the ready state.

If the reception apparatus 12 activates the first data broadcastapplication in response to the execute command while the first databroadcast application is in the ready state, then the first databroadcast application is placed into the active state.

If some other device acquires and activates the third data broadcastapplication in response to the execute command while the third databroadcast application is in the released state (i.e., yet to be acquiredby the device), then the third data broadcast application is placed intothe active state.

If the reception apparatus 12 fires an event on the currently executingfirst data broadcast application in response to the event command whilethe first data broadcast application is in the active state, then thefirst data broadcast application remains in the active state.

If the reception apparatus 12 suspends the currently executing firstdata broadcast application in response to the suspend command while thefirst data broadcast application is in the active state, then the firstdata broadcast application is placed into the suspended state. Also, ifthe reception apparatus 12 activates the second data broadcastapplication in response to the execute command for the second databroadcast application different from the first data broadcastapplication currently in the suspended state, then the second databroadcast application is placed into the active state. That is, if a CMis assumed to be inserted halfway into the digital TV program, forexample, then the second data broadcast application for CMs is executedwhile the first data broadcast application for the program is beingsuspended.

And if the reception apparatus 12 resumes the suspended first databroadcast application in response to the execute command while the firstdata broadcast application is in the suspended state, then the firstdata broadcast application is placed into the active state. Also, if thereception apparatus 12 terminates the currently executing second databroadcast application in response to the terminate command while thesecond data broadcast application is in the active state, then thesecond data broadcast application is placed into the ready state. Thatis, if the CM assumed above to be inserted halfway into the digital TVprogram is terminated, for example, the program is resumed. This in turnterminates the second data broadcast application for CMs and resumes thecurrently suspended first data broadcast application for the program.

Also, if the reception apparatus 12 terminates the currently executingfirst data broadcast application in response to the terminate commandwhile the first data broadcast application is in the active state, thenthe first data broadcast application is placed into the ready state.Furthermore, if the first data broadcast application is in the ready,active, or suspended state and if the application expiration date ofthis data broadcast application expires, then this data broadcastapplication is deleted from the cache memory 64 and registration of theapplication is erased, whereby the first data broadcast application isplaced into the released state.

[Trigger Information Handling Process]

Explained next in reference to the flowchart of FIG. 14 is the triggerinformation handling process to be performed by the reception apparatus12 upon receipt of trigger information.

FIG. 14 is a flowchart explanatory of the trigger information handlingprocess. This trigger information handling process is carried outrepeatedly while the user is viewing a digital TV program, i.e., whilethe reception apparatus 12 is receiving a digital TV broadcast signal.

In step S11, the trigger extraction portion 57 waits until triggerinformation is extracted from the video signal coming from the videodecoder 55. When the trigger information is extracted from the videosignal, control is passed on to step S12.

In step S12, the trigger extraction portion 57 analyzes the extractedtrigger information so as to determine whether step S13 and subsequentsteps have already been performed on (i.e., have handled) the trigger_idincluded in this trigger information. If it is determined that step S13and subsequent steps have already been carried out, control is returnedto step S11 and the process is repeated from there. If it is determinedthat step S13 and subsequent steps have yet to be performed on thistrigger information, control is passed on to step S13.

In step S13, the trigger extraction portion 57 determines whether thistrigger information is valid based on the trigger_validity included inthe trigger information. If it is determined that this triggerinformation is not valid, control is returned to step S11 and theprocess is repeated from there. If it is determined that this triggerinformation is valid, then control is passed on to step S14.

In step S14, the trigger extraction portion 57 determines whether or notto acquire a TPT based on the domain_name or program_id included in thetrigger information under control of the control portion 60. Forexample, if the user has changed the channel of the currently selecteddigital TV program so that the domain_name included in the triggerinformation has been changed correspondingly, the trigger extractionportion 57 determines that the TPT is to be acquired (“YES” in stepS14). And the trigger extraction portion 57 controls the communicationI/F 58 and requests the TPT by accessing the TPT server 13 determined bythe URL (e.g., “http://abc.tv/300?id=1”) that may be acquired by adding“http://” to the beginning of the trigger information, for example. Inresponse to the request from the reception apparatus 12, the TPT server13 determines the TPT and transmits the determined TPT to the receptionapparatus 12.

In step S15, the TPT analysis portion 59 controls the communication I/F58 to acquire the TPT coming from the TPT server 13. Also, the TPTanalysis portion 59 retains the acquired TPT (e.g., TPT in FIG. 10). Onthe other hand, if it is determined in step S14 that the TPT is not tobe acquired, step S15 is skipped and control is passed on to step S16since the TPT corresponding to the currently selected digital TV programis being held in the TPT analysis portion 59.

In step S16, based on the TPT from the TPT analysis portion 59, thecontrol portion 60 determines that the command corresponding to thetrigger information extracted by the trigger extraction portion 57 isthe register, execute, terminate, event, or suspend command. Morespecifically, according to the TPT in FIG. 10 for example, if thetrigger_id included in the trigger information is “1” as the commandcorresponding to this trigger information, the control portion 60determines that the command is the register command; if the trigger_idis “2,” the control portion 60 determines that the command is theexecute command. Also according to the TPT in FIG. 10, if the itemtrigger_id is “3,” the control portion 60 determines that the command isthe event command; if the trigger_id is “4,” the control portion 60determines that the command is the suspend command; and if thetrigger_id is “5,” the control portion 60 determines that the command isthe terminate command. That is, the TPT is used as a dictionary fordetermining the command using the trigger_id included in the triggerinformation.

Upon determining the command, the control portion 60 compares the valuesof the domain_name and program_id included in the trigger informationextracted by the trigger extraction portion 57, with the value of theprogram attribute in the TPT from the TPT analysis portion 59. Only ifthese values match, does the control portion 60 determine the commandcorresponding to the trigger information. If the values do not match,the TPT analysis portion 59 under control of the control portion 60again accesses the TPT server 13 in order to acquire the TPTcorresponding to the currently selected digital TV program. In thismanner, even if the appropriate TPT is not retained due to radiointerference or the like, the reception apparatus 12 can reliablydetermine the expected command.

In step S17, the control portion 60 determines whether the result of thedetermination in step S16 is the register command. If it is determinedthat the command is the register command, control is passed on to stepS18.

In step S18, the control portion 60 controls the communication I/F 58 toaccess the application server 14 corresponding to the application URLdetermined by the TPT in order to acquire the data broadcast applicationdetermined by the application ID. The data broadcast applicationacquired by the communication I/F 58 is retained in the cache memory 64.Also, the control portion 60 associates the acquired data broadcastapplication with its application expiration date and applicationretention priority, the associated date and priority being stored intothe memory 61. In this manner, the data broadcast application held inthe cache memory 64 is managed by the control portion 60 in accordancewith the expiration date and retention priority of the application.

Thereafter, control is returned to step S11 and the process is repeatedfrom there.

If it is determined in step S17 that the result of the determination instep S16 is not the register command, control is passed on to step S19.In step S19, the control portion 60 determines whether the result of thedetermination in step S16 is the execute command. If it is determinedthat the command is the execute command, control is passed on to stepS20.

In step S20, the application engine 63 under control of the controlportion 60 determines whether the data broadcast application determinedby the application ID in the TPT is suspended (i.e., in the suspendedstate). More specifically, the data broadcast application determined bythe application ID is determined to be in the suspended state if dataindicative of the application being suspended is saved in the savememory 65B.

If it is determined in step S20 that the data broadcast applicationdetermined by the application ID is not suspended, control is passed onto step S21. In step S21, the application engine 63 under control of thecontrol portion 60 acquires the data broadcast application determined bythe application ID if the application has yet to be acquired (i.e., notfound in the cache memory 64).

In step S22, the application engine 64 under control of the controlportion 60 terminates any currently executing data broadcastapplications. And in step S23, the application engine 64 under controlof the control portion 60 activates the data broadcast applicationdetermined by the application ID.

Also in step S20, if it is determined that the data broadcastapplication determined by the application ID is suspended (i.e., in thesuspended state), control is passed on to step S24.

In step S24, the application engine 63 under control of the controlportion 60 moves the data held in the save memory 65B to the work memory65A and activates the data broadcast application determined by theapplication ID. In this manner, the currently suspended data broadcastapplication determined by the application ID is resumed from itssuspended state. Thereafter, control is returned to step S11 and theprocess is repeated from there.

If it is determined in step S19 that the result of the determination instep S16 is not the execute command, control is passed on to step S25.In step S25, the control portion 60 determines whether the result of thedetermination in step S16 is the event command. If it is determined thatthe command is the event command, control is passed on to step S26.

In step S26, the control portion 60 controls the application engine 63to fire (i.e., execute) the event corresponding to the event ID of thecommand on the currently executing data broadcast application only ifthe application ID determined by the TPT coincides with the applicationID of the executing data broadcast application. Thereafter, control isreturned to step S11 and the process is repeated from there.

If it is determined in step S25 that the result of the determination instep S16 is not the event command, control is passed on to step S27. Instep S27, the control portion 60 determines whether the result of thedetermination in step S16 is the suspend command. If it is determinedthat the command is the suspend command, control is passed on to stepS28.

In step S28, the application engine 63 under control of the controlportion 60 saves into the save memory 65B the data indicative of thestatus of the currently executing data broadcast application (i.e., datacurrently written in the work memory 65A, including informationindicating the layer of the currently displayed information if theinformation has a hierarchical structure). Thereafter, control isreturned to step S11 and the process is repeated from there.

If it is determined in step S27 that the result of the determination instep S16 is not the suspend command, that means the determination instep S16 points to the terminate command. In this case, control ispassed on to step S29.

In step S29, the application engine 63 under control of the controlportion 60 terminates the data broadcast application determined by theapplication ID if the application is currently executing. In step S30,the application engine 63 under control of the control portion 60deletes from the work memory 65A and save memory 65B the data about thedata broadcast application determined by the application ID, and deletesthe data broadcast application from the cache memory 64. Thereafter,control is returned to step S11 and the process is repeated from there.

The preceding paragraph completes the explanation of the triggerinformation handling process. According to the above-described triggerinformation handling process, it is possible to activate a databroadcast application, fire an event on the data broadcast application,or terminate the data broadcast application in interlocked relation toTV broadcast audio video content (e.g., digital TV programs and CMs). Itis also possible to suspend the executing data broadcast applicationwith its execution status retained so as to execute or terminate anotherdata broadcast application, before resuming the suspended data broadcastapplication from its suspended state.

[Operation Scenario]

When the reception apparatus 12 performs the above-described triggerinformation handling process, it is possible to operate the databroadcast application as illustrated in FIG. 15 for example.

FIG. 15 shows a typical operation scenario.

In FIG. 15, while the digital TV program corresponding to the digital TVbroadcast signal from the broadcast unit 11 is displayed on the displaydevice, the reception apparatus 12 continuously extracts triggerinformation. And if the domain_name or program_id included in thetrigger information has changed, the reception apparatus 12 sends aquery for a TPT to the TPT server 13 by accessing the URL acquired byadding the character string “http://” to the trigger information. Inthis manner, the reception apparatus 12 can acquire the TPT from the TPTserver 13 and retain the acquired TPT.

Thereafter, the reception apparatus 12 continuously extracts the triggerinformation and, with the trigger information extracted, determines thecommand corresponding to the trigger information based on the TPT. Forexample, if the command determined by the trigger information“abc.tv/300?id=1” is the register command, the reception apparatus 12accesses the application server 14 corresponding to the application URL,acquires the data broadcast application therefrom, and registers theacquired data broadcast application. Furthermore, if the already handledtrigger information (“abc.tv/300?id=1” is received, the receptionapparatus 12 ignores that trigger information (indicated as “repeat” inFIG. 15).

The reception apparatus 12 continuously extracts the trigger informationthereafter. If the command determined by the trigger information“abc.tv/300?id=2” is the execute command, the acquired data broadcastapplication is activated. This causes the display device to displayprogram-related information (indicated as “Video SynchronizedApplication” in FIG. 15) in a manner superposed on the digital TVprogram.

Further, the reception apparatus 12 continuously extracts the triggerinformation. If the command determined by the trigger information“abc.tv/300?id=3” is the event command, an event is fired into thecurrently executing data broadcast application. This causes the displaydevice to change the substance of the program-related informationdisplayed in a manner superposed on the digital TV program.

And if the command determined by the trigger information“abc.tv/300?id=5” is the terminate command, the reception apparatus 12terminates the currently executing data broadcast application. Thiscauses the display device to turn off the program-related informationsuperposed on the digital TV program, leaving only the programdisplayed.

As explained above, the reception apparatus 12 can determine the commandcorresponding to the trigger information from the broadcast unit 11 byretaining the TPT corresponding to the server determination information(domain_name) or content identification information (program_id). Thismakes it possible to implement the operation scenario shown in FIG. 15.

Second Embodiment Typical Configuration of the Communication System

The foregoing description explained examples in which the digital TVbroadcast signal of audio video content such as digital TV programs istransmitted from the broadcast unit 11. Alternatively, the audio videocontent may be distributed by VOD (Video On Demand) via the Internet 20.

FIG. 16 shows a communication system 81 embodying the presentdisclosure.

Of the components shown in FIG. 16, those whose correspondingcounterparts are found in FIG. 1 are designated by like referencenumerals, and their explanations may be omitted where appropriate.

That is, compared with FIG. 1, FIG. 16 shows a distribution server 91replacing the broadcast unit 11 and connected to the Internet 20. Inresponse to requests from the reception apparatus 12, the distributionserver 91 distributes audio video content such as VOD content to thereception apparatus 12 via the Internet 20. Also, the distributionserver 91 transmits trigger information together with the VOD content tothe reception apparatus 12.

The reception apparatus 12 extracts the trigger information transmittedalong with the VOD content from the distribution server 91, and acquiresfrom the TPT server 13 the TPT corresponding to the item “domain_name”or “program_id” included in the extracted trigger information. And basedon the TPT from the TPT server 13, the reception apparatus 12 determinesthe command corresponding to the trigger information from thedistribution server 91. In response to the command thus determined, thereception apparatus 12 controls the operation of the data broadcastapplication executed in interlocked relation to the VOD content.

In this manner, the reception apparatus 12 receives audio video contentnot only through the broadcasting network but also via the communicationnetwork. Whether the audio video content is received from thebroadcasting network or from the communication network, the receptionapparatus 12 can acquire the TPT corresponding to the serverdetermination information (domain_name) or content identificationinformation (program_id) included in the trigger information transmittedalong with the audio video content of interest. As a result, thereception apparatus 12 can determine the command corresponding to thetrigger information based on the acquired TPT.

The foregoing description showed examples in which a plurality ofservers such as the TPT server 13 and application servers 14 areprovided to implement different functions being offered. Alternatively,part or all of these functions may be offered collectively by a singleserver or by a plurality of servers.

As explained above, according to this technology, it is possible toprovide data broadcast applications that are executed in interlockedrelation to audio video content such as digital TV programs and VODcontent.

Furthermore, the trigger information can also be given to the receptionapparatus 12 through a dedicated terminal such as the set-top box. Thusthe broadcasting system 1 can offer data broadcast applications withoutrecourse to renovating its broadcast transmission channel equipment suchas the CATV network as well as its dedicated terminals. Also, there isno need to perform such work as obtaining permission from the broadcastoperator relaying programs.

[Explanation of the Computer to which this Technology is Applied]

The series of processes described above may be executed either byhardware or by software. Where the software-based series of processingis to be carried out, the programs constituting the software may beinstalled into any suitable computer for execution. The computers mayinclude those with the software incorporated in their dedicated hardwarebeforehand, and those such as general-purpose personal computers or thelike capable of executing diverse functions based on diverse programsinstalled therein.

FIG. 17 is a block diagram showing a typical hardware structure of acomputer for executing the above-described series of processing based onprograms.

In the computer, a CPU (Central Processing Unit) 101, a ROM (Read OnlyMemory) 102, and a RAM (Random Access Memory) 103 are interconnected viaa bus 104.

An input/output interface 105 is further connected to the bus 104. Theinput/output interface 105 is connected with an input portion 106, anoutput portion 107, a recording portion 108, a communication portion109, and a drive 110.

The input portion 106 is typically made up of a keyboard, a mouse, and amicrophone. The output portion 107 is usually composed of a displaydevice and speakers. The recording portion 108 is generally constitutedby a hard disk and a nonvolatile memory. The communication portion 109is formed by a network interface or the like. The drive 110 drivesremovable media 111 such as magnetic disks, optical disks,magneto-optical disks, or semiconductor memories.

In the computer structured as outlined above, the above-described seriesof processing is carried out, for example, by the CPU 101 that loadsprograms stored in the recording portion 108 into the RAM 103 forexecution through the input/output interface 105 and bus 104.

The programs to be executed by the computer (i.e., by CPU 101) may beoffered recorded on the removable media 111 typically prepared aspackaged media. Also, the programs may be offered via wired or wirelesstransmission media such as local area networks, the Internet, anddigital satellite broadcasts.

In the computer, the programs may be installed into the recordingportion 108 via the input/output interface 105 from the removable media111 loaded in the drive 110. Also, the programs may be received by thecommunication portion 109 via wired or wireless transmission media andinstalled into the recording portion 108. Alternatively, the programsmay be preinstalled in the ROM 102 or in the recording portion 108.

Incidentally, the programs may be processed chronologically in thesequence explained in this specification, or may be processed inparallel or in otherwise appropriately timed fashion such as when theyare invoked.

In this specification, the processing steps that describe the programsfor causing the computer to perform various processes need notnecessarily be processed chronologically in the sequence depicted asflowcharts; the steps may also include those processed parallelly orindividually (e.g., in paralleled or object-oriented fashion).

Also, the programs may be processed by a single computer or by aplurality of computers on a distributed basis. The programs may also betransferred to a remote computer or computers for execution.

Furthermore, in this specification, the term “system” means an aggregateof a plurality of component elements (apparatuses, modules (parts),etc.). All component elements may or may not be housed in a singleenclosure. Therefore, a plurality of apparatuses each housed in aseparate enclosure and connected via a network are considered a network,and a single apparatus formed by a plurality of modules housed in asingle enclosure are also regarded as a system.

Also, it should be understood that this technology when embodied is notlimited to the above-described embodiments and that variousmodifications, variations and alternatives may be made of thistechnology so far as they are within the spirit and scope thereof.

For example, this technology may be structured for cloud computingwhereby a single function is shared and processed in collaboration amonga plurality of apparatuses via a network.

Also, each of the steps explained in reference to the above-describedflowcharts may be executed not only by a single apparatus but also by aplurality of apparatuses in a shared manner.

Furthermore, if one step includes a plurality of processes, theseprocesses included in the step may be performed not only by a singleapparatus but also by a plurality of apparatuses in a shared manner.

Furthermore, this technology may be structured as follows:

(1)

A reception apparatus including:

a reception portion configured to receive audio video content;

a trigger extraction portion configured to extract trigger informationfor operating an application program transmitted along with the audiovideo content and executed in interlocked relation to the audio videocontent;

a table acquisition portion configured to acquire a correspondence tablefor associating the trigger information with commands for controllingthe operation of the application program;

a command determination portion configured such that, based on theacquired correspondence table, the command determination portiondetermines the commands associated with the extracted triggerinformation; and

a control portion configured to control the operation of the applicationprogram in response to the determined commands.

(2)

The reception apparatus described in (1) above, further including:

an output portion configured to output the audio video content, or theaudio video content as well as the application program;

wherein the table acquisition portion acquires the correspondence tableif the audio video content being output is changed in substance.

(3)

The reception apparatus described in (1) or (2) above, wherein

the trigger information includes determination information fordetermining an information processing apparatus providing thecorrespondence table and first identification information foridentifying the audio video content; and

if the determination information or the first identification informationincluded in the extracted trigger information is changed, the tableacquisition portion acquires the correspondence table from theinformation processing apparatus in accordance with the determinationinformation and the first identification information.

(4)

The reception apparatus described in (3) above, wherein

the correspondence table further associates the trigger information andthe commands with second identification information for identifying theapplication program; and

the command determination portion determines the commands associatedwith the trigger information regarding each of the application programsidentified by the second identification information associated with theextracted trigger information.

(5)

The reception apparatus described in any one of (1) through (4) above,wherein the control portion controls the operation of one or a pluralityof the application programs in response to the determined commands.

(6)

The reception apparatus in any one of (1) through (5) above, wherein

the trigger information includes information indicative of theprobability of the trigger information itself becoming effective; and

if the trigger information becomes effective, the control portioncontrols the operation of the application program in response to thecommands.

(7)

The reception apparatus described in any one of (1) through (6) above,wherein

the commands designate acquisition or registration, acquisition oractivation, firing of an event, suspension, or termination of theapplication program; and

in response to each of the commands, the control portion controlsacquisition or registration, acquisition or activation of theapplication program, firing of an event into the currently executingapplication program, suspension, or termination of the currentlyexecuting application program.

(8)

A reception method for use with a reception apparatus, the receptionmethod executing the reception apparatus to include:

receiving audio video content;

extracting trigger information for operating an application programtransmitted along with the audio video content and executed ininterlocked relation to the audio video content;

acquiring a correspondence table for associating the trigger informationwith commands for controlling the operation of the application program;

based on the acquired correspondence table, determining the commandsassociated with the extracted trigger information; and

controlling the operation of the application program in response to thedetermined commands.

(9)

A program for causing a computer to function as:

a reception portion configured to receive audio video content;

a trigger extraction portion configured to extract trigger informationfor operating an application program transmitted along with the audiovideo content and executed in interlocked relation to the audio videocontent;

a table acquisition portion configured to acquire a correspondence tablefor associating the trigger information with commands for controllingthe operation of the application program;

a command determination portion configured such that, based on theacquired correspondence table, the command determination portiondetermines the commands associated with the extracted triggerinformation; and

a control portion configured to control the operation of the applicationprogram in response to the determined commands.

(10)

An information processing system including:

a reception apparatus;

a first information processing apparatus; and

a second information processing apparatus,

the reception apparatus including

-   -   a reception portion configured to receive audio video content,    -   a trigger extraction portion configured to extract trigger        information for operating an application program transmitted        along with the audio video content and executed in interlocked        relation to the audio video content,    -   a table acquisition portion configured to acquire from the first        information processing apparatus a correspondence table for        associating the trigger information with commands for        controlling the operation of the application program,    -   a command determination portion configured to determine, based        on the acquired correspondence table, the commands associated        with the extracted trigger information, and    -   a control portion configured to control the operation of the        application program acquired from the second information        processing apparatus in response to the determined commands,

the first information processing apparatus including

-   -   a first provision portion configured to provide the        correspondence table in response to a query from the reception        apparatus, and

the second information processing apparatus including

-   -   a second provision portion configured to provide the application        program in response to a query from the reception apparatus.

What is claimed is:
 1. A reception apparatus comprising: a receptionportion configured to receive audio video content; a trigger extractionportion configured to extract trigger information for operating anapplication program transmitted along with said audio video content andexecuted in interlocked relation to said audio video content; a tableacquisition portion configured to acquire a correspondence table forassociating said trigger information with commands for controlling theoperation of said application program; a command determination portionconfigured such that, based on the acquired correspondence table, saidcommand determination portion determines said commands associated withthe extracted trigger information; and a control portion configured tocontrol the operation of said application program in response to thedetermined commands.
 2. The reception apparatus according to claim 1,further comprising: an output portion configured to output said audiovideo content, or said audio video content as well as said applicationprogram; wherein said table acquisition portion acquires saidcorrespondence table if said audio video content being output is changedin substance.
 3. The reception apparatus according to claim 2, whereinsaid trigger information includes determination information fordetermining an information processing apparatus providing saidcorrespondence table or first identification information for identifyingsaid audio video content; and if said determination information or saidfirst identification information included in the extracted triggerinformation is changed, said table acquisition portion acquires saidcorrespondence table from said information processing apparatus inaccordance with said determination information and said firstidentification information.
 4. The reception apparatus according toclaim 3, wherein said correspondence table further associates saidtrigger information and said commands with second identificationinformation for identifying said application program; and said commanddetermination portion determines said commands associated with saidtrigger information regarding each of the application programsidentified by said second identification information associated with theextracted trigger information.
 5. The reception apparatus according toclaim 4, wherein said control portion controls the operation of one or aplurality of said application programs in response to the determinedcommands.
 6. The reception apparatus according to claim 1, wherein saidtrigger information includes information indicative of the probabilityof said trigger information itself becoming effective; and if saidtrigger information becomes effective, said control portion controls theoperation of said application program in response to said commands. 7.The reception apparatus according to claim 1, wherein said commandsdesignate acquisition or registration, acquisition or activation, firingof an event, suspension, or termination of said application program; andin response to each of said commands, said control portion controlsacquisition or registration, acquisition or activation of saidapplication program, firing of an event into the currently executingapplication program, suspension, or termination of said currentlyexecuting application program.
 8. A reception method for use with areception apparatus, said reception method executing said receptionapparatus to comprise: receiving audio video content; extracting triggerinformation for operating an application program transmitted along withsaid audio video content and executed in interlocked relation to saidaudio video content; acquiring a correspondence table for associatingsaid trigger information with commands for controlling the operation ofsaid application program; based on the acquired correspondence table,determining said commands associated with the extracted triggerinformation; and controlling the operation of said application programin response to the determined commands.
 9. A program for causing acomputer to function as: a reception portion configured to receive audiovideo content; a trigger extraction portion configured to extracttrigger information for operating an application program transmittedalong with said audio video content and executed in interlocked relationto said audio video content; a table acquisition portion configured toacquire a correspondence table for associating said trigger informationwith commands for controlling the operation of said application program;a command determination portion configured such that, based on theacquired correspondence table, said command determination portiondetermines said commands associated with the extracted triggerinformation; and a control portion configured to control the operationof said application program in response to the determined commands. 10.An information processing system comprising: a reception apparatus; afirst information processing apparatus; and a second informationprocessing apparatus, said reception apparatus including a receptionportion configured to receive audio video content, a trigger extractionportion configured to extract trigger information for operating anapplication program transmitted along with said audio video content andexecuted in interlocked relation to said audio video content, a tableacquisition portion configured to acquire from said first informationprocessing apparatus a correspondence table for associating said triggerinformation with commands for controlling the operation of saidapplication program, a command determination portion configured todetermine, based on the acquired correspondence table, said commandsassociated with the extracted trigger information, and a control portionconfigured to control the operation of said application program acquiredfrom said second information processing apparatus in response to thedetermined commands, said first information processing apparatusincluding a first provision portion configured to provide saidcorrespondence table in response to a query from said receptionapparatus, and said second information processing apparatus including asecond provision portion configured to provide said application programin response to a query from said reception apparatus.